Copper base alloys containing iron, aluminum, and zinc



United States Patent 3,146,095 COPHER BASE ALLOY CQNTAINING IRON,

ALEJMENUM, AND ZINC Carl J. Hechinger, St. Louis, Mo., assignor to (BlinMathieson Chemical Corporation, a corporation of Virginia No Drawing.Filed May 6, 1963, Ser. No. 278,404

2 Claims. (Cl. 75--153) The present invention relates to improved copperbase alloys containing iron, aluminum, and zinc.

It is an object of the present invention to provide new and improvedcopper base alloys.

It is a further object of the present invention to provide copper basealloys as above which are characterized by improved properties,especially greater strength and excellent anneal to temper properties.

It is a still further object of the present invention to provideimproved copper base alloys as above which are inexpensive and easilyobtainable.

Further objects and advantages will appear hereinafter.

In accordance with the present invention it has now been found that theforegoing objects may be readily accomplished and a new and improvedcopper base alloy obtained which consists essentially of from 0.75 to1.25 percent by weight of iron, 1.25 to 2.00 percent by weight aluminum,65 to 67 percent by weight copper and the remainder zinc.

The present invention relates to new and improved cop per base alloyscontaining the above ingredients and characterized by low cost andsurprisingly good properties, for example, excellent strength andexcellent anneal to temper properties.

In accordance with the findings of the present invention the ranges ofingredients must critically be within the aforesaid amounts, forexample, if 67 percent copper is exceeded, the alloy hasnon-reproducible properties, and if the copper is in an amount less than65 percent the alloy has good hot rolling characteristics but theductility markedly affected. Such an alloy cannot be cold rolled morethan 35 percent; whereas, the alloy of the present invention can bereduced 70 percent with ease by cold rolling from soft temper.

The iron and aluminum contents are similarly critical in the aboveranges, for example, when iron is lower than 0.75 percent the elongationis decreased to less than 41 percent minimum at 0.020 mm. grain which isobtained by this alloy. Iron in percentages less than 0.75 percent willalso enhance the formation of beta phase since the proper aluminum toiron ratio needed to form soluble phase of this combination of elementsis not present. When iron exceeds 1.25 percent, free iron is noted inthe microstructure which detracts from ductility, malleability andstrength of the alloy.

When the alloy has an aluminum content less than 1.25 percent thestrength of the alloy is insufficient. The formation of the iron andaluminum phase is prevented and free iron in the microstructure can beobserved which in itself detracts from the formability and strength ofthe alloy. Exceeding the maximum of 2 percent aluminum can result in theformation of beta phase which has deleterious effect on the coldrollability and formability of the alloy.

Varying amounts of impurities may be tolerated in the alloy of thepresent invention, for example, representative tolerances include: lead,up to 0.02 percent; bismuth, up to 0.001 percent; arsenic, up to 0.01percent; antimony, up to 0.001 percent; nickel, up to 0.03 percent;phosphorus, up to 0.001 percent; manganese, up to 0.03 percent; silver,up to 0.05 percent; silicon, up to 0.03 percent;' chromium, up to 0.001percent; beryllium,

up to 0.005 percent; cadmium, up to 0.005 percent; and tin, up to 0.10percent.

The present invention and improvements thereof will be more readilyapparent from a consideration of the following illustrative examples.

EXAMPLE 1 An alloy was prepared having the following proximatecomposition:

Percent Copper 66.5 Iron 1.0 Aluminum 1.4 Zinc Remainder This alloy hasgreater ultimate and yield strength than the strongest alpha brasseswhen rolled to comparable tempers, as shown in Table 1 below, whereinthe cartridge brass has a composition of about 70 percent copper and 30percent Zinc.

Table 1 Cartridge Brass Present Alloy Percent Reduction Tensile, Yield,Tensile, Yield,

psi. p.s.i. p.s.i. p.s.1.

Annealed (0.025 mm.) 51, 000 18,000 65,000 24, 000 10 l- 58, 000 38, 00068, 000 44, 000 20 06, 000 52, 000 74, 000 00, C00 30 75, 000 60, 00084, 000 71, 000 40 4, 000 67, 500 95, 000 78, 000 50 91, 000 74, 000101,000 83, 000 60 97, 000 78, 000 105, 000 87, 000

EXAMPLE 2 The alloy of Example 1 exhibits better anneal-to-temperproperties than cartridge brass after 70 percent reduction, as shown inTable 2 below, wherein the cartridge brass has a composition of about 70percent copper and 30 percent zinc.

Table 2 Tensile Tensile Strength Strength Annealing Temperature (p.s.i.)(p.s.1.)

Cartridge Present Brass Alloy This lnvention may be embodied in otherforms or carried out in other ways without departing from the spirit oressential characteristics thereof. The present embodiment is thereforeto be considered as in all respects illustrative and not restrictive,the scope of the invention being indicated by the appended claims, andall changes which come within the meaning and range of equivalency areintended to be embraced therein.

What is claimed is:

1. An alloy consisting essentially of from 0.75 to 1.25 percent byweight of iron, 1.25 to 2 percent aluminum, 29.75 to 33 percent zinc andthe balance copper.

2. An alloy consisting essentially of 1.0 percent iron, 1.4 percentaluminum, 31.1 percent zinc and the balance copper.

References Cited in the file of this patent FOREIGN PATENTS

1. AN ALLOY CONSISTING ESSENTIALLY OF FROM 0.75 TO 1.25 PERCENT BYWEIGHT OF IRON, 1.25 TO 2 PERCENT ALUMINUM, 29.75 TO 33 PERCENT ZINC ANDTHE BALANCE COPPER.